Investigation into the causal relationship between peripheral neurophathy and vascular disease of the lower limb in patients with diabetes mellitus, by ultrastructural examination of biopsy tissue. An electron microscopic study will be made of the innervation of small blood vessels and arteries of the lower limb in patients with diabetes mellitus. Pathological lesions of the arteries will be examined at different stages of the development and progress of peripheral vascular disease. A qualitative study is being made of the innervation of these blood vessels in both diabetics, and non-diabetic controls. An ultrastructural study will also be made of the effect of surgical lumbar sympathectomy on the progression of vascular disease in diabetics as compared to the non-diabetics, when such a procedure is clinically mandated. BIBLIOGRAPHIC REFERENCES: Deficient vascular innervation in familial dysautonomia, an explanation for vasomotor instability. N. Grover-Johnson and J. Pearson. Neuropath. and Appl. Neurobiol. 2:217-224, 1976. Ultrastructural evidences of a decrease in the autonomic nerves which innervate small blood vessels in diabetes mellitus. Ultrastructural evidence of a decrease in the autonomic nerves which innervate small blood vessels in diabetes mellitus. N. Grover-Johnson and G.E. Kim. J. Neuropath. and Exptl. Neurol. 35: 336, 1976.